Results   
We test our models with the inference procedure from DDPM [1]} and DDIM [2]}. In Tab. REF  we provide the FID score for CelebA (64x64) dataset [3]} (under non-commercial research purposes license). As can be seen for DDPM inference procedure for \(10,20,50,100\)  steps, the best results were obtained from the Gamma model, which improves results by a gap of 264 FID scores for ten iterations. For 100 iterations, the Gamma model improves results by 31 FID scores. For 1000 iterations, the best results were obtained from the DDPM model. Nevertheless, our Gamma model obtains results that are closer to the DDPM by a gap of \(0.83\) . For the DDIM procedure, the best results were obtained with the Gamma model for all number of iterations. Fig. REF  presents samples generated by the three models. Our models provide better quality images when compared to DDPM and DDIM methods.
